Moderna Inc. and Merck & Co. said Wednesday that a personalized mRNA cancer vaccine significantly reduced melanoma recurrence and spread in a Phase 3 trial [4, 5].
This development represents a potential shift in oncology treatment, addressing a critical gap in care for patients with high-risk skin cancer. Because melanoma causes the majority of skin-cancer deaths despite accounting for roughly one% of cases [3], a preventative treatment for recurrence could save thousands of lives.
The vaccine, named intismeran [4], was used in combination with Merck's immunotherapy drug Keytruda. The trial focused on preventing the return of melanoma after initial treatment. The companies said the combined therapy showed a significant reduction in the likelihood of the cancer returning or spreading to other organs [1, 2].
Investor reaction to the results was immediate and volatile. Moderna shares rose between 150% [2] and more than 176% [1] before experiencing a pullback. Merck shares also saw a sharp increase following the announcement. The companies disclosed the results to investors in the U.S., with shares trading on the NASDAQ and NYSE [1, 2].
The personalized nature of the vaccine means it is tailored to the specific genetic mutations of an individual patient's tumor. This approach aims to train the immune system to recognize and attack remaining cancer cells that may have survived initial surgery.
If regulatory approvals proceed as expected, a commercial launch for the treatment could occur in 2027 [6].
“Moderna and Merck reported a significant reduction in melanoma recurrence in a Phase 3 trial.”
The success of intismeran validates the application of mRNA technology beyond infectious diseases and into personalized oncology. By combining a tailored vaccine with an existing checkpoint inhibitor like Keytruda, the partnership is attempting to create a 'one-two punch' that prevents relapse in the most aggressive form of skin cancer. This could pave the way for similar personalized mRNA vaccines for other solid tumors.
